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HelpTest Code LAB3413 Prothrombin Variant DNA
Clinical System Name
Prothrombin Variant DNA
Synonyms
Factor 2-DNA
Factor II-DNA
Factor 2 Gene Mutation
Factor II Gene Mutation
Prothrombin 20210
Prothrombin 20210A
Prothrombin Mutation
Prothrombin II Mutation
PT 20210
Description
This test determines the presence or absence of the 20210G (normal) and 20210A (variant) alleles in the prothrombin gene.
Prothrombin (factor II) is one of the blood coagulation factors. A variant (commonly known as nucleotide 20210G>A; G20210A) in the 3' untranslated region of the prothrombin gene (F2) is associated with an increased risk for venous thrombosis. Approximately 20% of Dutch patients with a family history of venous thrombosis are heterozygotes for the 20210A allele, as compared to about 1% of healthy controls. In a population-based study, the 20210A allele appears to increase the risk of venous thrombosis about 3-fold for adults of both sexes. This test determines the presence or absence of the 20210G (normal) and 20210A (variant) alleles in the prothrombin gene.
Note that this test can be ordered individually or as part of a thrombosis risk panel (LAB3498) that includes the factor V Leiden variant.
Sample Requirements
Specimen: Whole Blood
Container(s): Lavender/EDTA, Yellow/ACD A or B, or Lt. Blue/Citrate
Preferred Vol: 3.0 mL
Minimum Vol: 2.0 mL
Only one sample is needed to perform both Factor V Leiden and Prothrombin Variant.
Specimen: DNA
Container(s): Sterile plastic tube
Preferred Vol: 20-30 ul of 100ng/ul concentration
Note: Only one sample is needed to perform both Factor V Leiden and Prothrombin Variant.
Alternative Specimen (e.g. salvia or buccal): Alternate Specimen Collection Kits for Genetic Testing
Processing Instructions
Reject due to: Heparin green top tubes
Spin: N
Aliquot: N
Temp: 2 - 4 C
Storage location: CPA refrigerator Send Outs rack.
Stability
| Specimen Type | Temperature | Time |
|---|---|---|
| Whole Blood | Room temp | 3 d |
| Refrigerated | 7 d | |
| Frozen | Unacceptable | |
| Extracted DNA | Room temp | 3-4 d |
| Refrigeratd | 1 y | |
| Frozen | Indefinitely |
Availability
| STAT | Performed | TAT |
|---|---|---|
| Contact Lab | Weekly | 2 w |
Performing Laboratory
University of Washington
Department of Laboratory Medicine
Genetics Lab
1959 NE Pacific St, NW220
Seattle, WA 98195
Phone Number: (206) 520-4600
Department
Department: Send Outs/Genetic
Phone Number: (206) 987-2563
Reference Range
Interpretive report will be provided.
Methodology
Method: Next-generation sequencing is performed to detect the variant F2 allele. In Human Genome Variation Society nomenclature, this variant is officially designated as NM_000506.4:c.*97G>A. This test was developed and its performance characteristics determined by the Department of Laboratory Medicine at the University of Washington.
Clinical Utility
Prothrombin-Related Thrombophilia GeneReview
The common c.20210G>A mutation in the F2 gene is associated with elevated prothrombin levels, which promotes development of fibrin clots. 2-4 % of the population is heterozygous for this mutation. Heterozygotes may have an estimated 3-11 fold increased risk of thrombosis. The risk of venous thrombosis recurrence is higher in individuals who also carry other thrombosis risk factors.
Note that this test can be ordered individually or as part of a thrombosis risk panel (LAB3498) that includes he factor V Leiden variant.
Send Out Instructions
| Reference Test Name: | Prothrombin DNA Screen |
| Reference Test Number: | PRODS |
| Instructions: | Send out Monday through Friday with the UW courier. |
Exclude from UM database